Asks for nude or underwear photos "to assess you"
Agencies assess new faces with polaroids: plain clothes, natural light, no make-up. Nobody legitimate needs anything else to assess you.
Real agencies and casting directors evaluate new faces with digitals or polaroids: simple photos in plain, fitted clothes, natural light, no make-up, no retouching. That is the industry standard, in every country, and it is what you should send when asked for photos.
Requests for photos in underwear, swimwear "to see your body", topless or nude "to assess your potential" are not part of any legitimate assessment. Even for lingerie or swimwear work, the casting is done through a real, verifiable agency, in a studio or office, never through a private message asking you to undress first.
If someone asks for these photos, do not negotiate and do not send "just one". Stop the conversation, keep the messages, and report the profile where you met them. Photos obtained this way are also the raw material of blackmail.